Implement "create an element" when sync for Custom Element V1

third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.h

Index: third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.h
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.h b/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.h
index fb46146a12422198b4964149c9e4ca49ee22a1ac..5f6dcb888d5654190cfffb84a09debc39a2c5aee 100644
--- a/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.h
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElementDefinition.h
@@ -13,8 +13,10 @@
 
 namespace blink {
 
-class ScriptState;
 class Element;
+class ExceptionState;
+class HTMLElement;
+class QualifiedName;
 
 class CORE_EXPORT CustomElementDefinition
     : public GarbageCollectedFinalized<CustomElementDefinition> {
@@ -41,11 +43,17 @@ public:
         return m_constructionStack;
     }
 
+    virtual HTMLElement* createElementSync(Document&, const QualifiedName&) = 0;
+    virtual HTMLElement* createElementSync(Document&, const QualifiedName&, ExceptionState&) = 0;
+    HTMLElement* createElementAsync(Document&, const QualifiedName&);
+
     void upgrade(Element*);
 
 protected:
     virtual bool runConstructor(Element*) = 0;
 
+    static void checkConstructorResult(Element*, Document&, const QualifiedName&, ExceptionState&);
+
 private:
     const CustomElementDescriptor m_descriptor;
     ConstructionStack m_constructionStack;